Merge pull request desktop#14744 from desktop/remember-zoom-level-on-…

…windows

Remember zoom level on update

app/src/lib/ipc-shared.ts

@@ -76,6 +76,7 @@ export type RequestChannels = {
   'set-native-theme-source': (themeName: ThemeSource) => void
   'focus-window': () => void
   'notification-event': NotificationCallback<DesktopAliveEvent>
+  'set-window-zoom-factor': (zoomFactor: number) => void
 }
 
 /**

app/src/lib/local-storage.ts

@@ -50,7 +50,7 @@ export function setBoolean(key: string, value: boolean) {
 }
 
 /**
- * Retrieve a `number` value from a given local storage entry if found, or the
+ * Retrieve a integer number value from a given local storage entry if found, or the
  * provided `defaultValue` if the key doesn't exist or if the value cannot be
  * converted into a number
  *
@@ -77,6 +77,34 @@ export function getNumber(
   return value
 }
 
+/**
+ * Retrieve a floating point number value from a given local storage entry if
+ * found, or the provided `defaultValue` if the key doesn't exist or if the
+ * value cannot be converted into a number
+ *
+ * @param key local storage entry to read
+ * @param defaultValue fallback value if unable to find key or valid value
+ */
+export function getFloatNumber(key: string): number | undefined
+export function getFloatNumber(key: string, defaultValue: number): number
+export function getFloatNumber(
+  key: string,
+  defaultValue?: number
+): number | undefined {
+  const numberAsText = localStorage.getItem(key)
+
+  if (numberAsText === null || numberAsText.length === 0) {
+    return defaultValue
+  }
+
+  const value = parseFloat(numberAsText)
+  if (isNaN(value)) {
+    return defaultValue
+  }
+
+  return value
+}
+
 /**
  * Set the provided key in local storage to a numeric value, or update the
  * existing value if a key is already defined.

app/src/lib/stores/app-store.ts

@@ -76,6 +76,7 @@ import {
   getCurrentWindowZoomFactor,
   updatePreferredAppMenuItemLabels,
   updateAccounts,
+  setWindowZoomFactor,
 } from '../../ui/main-process-proxy'
 import {
   API,
@@ -205,6 +206,7 @@ import {
   getEnum,
   getObject,
   setObject,
+  getFloatNumber,
 } from '../local-storage'
 import { ExternalEditorError, suggestedExternalEditor } from '../editors/shared'
 import { ApiRepositoriesStore } from './api-repositories-store'
@@ -575,13 +577,41 @@ export class AppStore extends TypedBaseStore<IAppState> {
   }
 
   private initializeZoomFactor = async () => {
-    const zoomFactor = await getCurrentWindowZoomFactor()
+    const zoomFactor = await this.getWindowZoomFactor()
     if (zoomFactor === undefined) {
       return
     }
     this.onWindowZoomFactorChanged(zoomFactor)
   }
 
+  /**
+   * On Windows OS, whenever a user toggles their zoom factor, chromium stores it
+   * in their `%AppData%/Roaming/GitHub Desktop/Preferences.js` denoted by the
+   * file path to the application. That file path contains the apps version.
+   * Thus, on every update, the users set zoom level gets reset as there is not
+   * defined value for the current app version.
+   * */
+  private async getWindowZoomFactor() {
+    const zoomFactor = await getCurrentWindowZoomFactor()
+    // One is the default value, we only care about checking the locally stored
+    // value if it is one because that is the default value after an
+    // update
+    if (zoomFactor !== 1 || !__WIN32__) {
+      return zoomFactor
+    }
+
+    const locallyStoredZoomFactor = getFloatNumber('zoom-factor')
+    if (
+      locallyStoredZoomFactor !== undefined &&
+      locallyStoredZoomFactor !== zoomFactor
+    ) {
+      setWindowZoomFactor(locallyStoredZoomFactor)
+      return locallyStoredZoomFactor
+    }
+
+    return zoomFactor
+  }
+
   private onTokenInvalidated = (endpoint: string) => {
     const account = getAccountForEndpoint(this.accounts, endpoint)
 
@@ -804,6 +834,7 @@ export class AppStore extends TypedBaseStore<IAppState> {
     this.windowZoomFactor = zoomFactor
 
     if (zoomFactor !== current) {
+      setNumber('zoom-factor', zoomFactor)
       this.updateResizableConstraints()
       this.emitUpdate()
     }

app/src/main-process/app-window.ts

@@ -416,6 +416,10 @@ export class AppWindow {
     return this.window.webContents.zoomFactor
   }
 
+  public setWindowZoomFactor(zoomFactor: number) {
+    this.window.webContents.zoomFactor = zoomFactor
+  }
+
   /**
    * Method to show the save dialog and return the first file path it returns.
    */

app/src/main-process/main.ts

@@ -515,6 +515,10 @@ app.on('ready', () => {
     mainWindow?.getCurrentWindowZoomFactor()
   )
 
+  ipcMain.on('set-window-zoom-factor', (_, zoomFactor: number) =>
+    mainWindow?.setWindowZoomFactor(zoomFactor)
+  )
+
   /**
    * An event sent by the renderer asking for a copy of the current
    * application menu.

app/src/ui/main-process-proxy.ts

@@ -155,6 +155,9 @@ export const getCurrentWindowZoomFactor = invokeProxy(
   0
 )
 
+/** Tell the main process to set the current window's zoom factor */
+export const setWindowZoomFactor = sendProxy('set-window-zoom-factor', 1)
+
 /** Tell the main process to check for app updates */
 export const checkForUpdates = invokeProxy('check-for-updates', 1)